Variable height scaffold assembly



April 1961 E. J. Dl CAMILLOI ETAL 2,978,062

VARIABLE HEIGHT SCAFFOLD ASSEMBLY Filed June 18, 1957 3 Sheets-Sheet 1INVENTOR. EUGENE J. D! CAMILLO DONALD I. SMITH April 4, 1961 Filed June18, 1957 E. J. DI CAMILLO ETAL VARIABLE HEIGHT SCAFFOLD ASSEMBLY 5Sheets-Sheet 2 INVENTOR. EUGENE J. DI CAMILLO DONALD I. SMITH April 1951E. J. Dl CAMILLO ETAL 2,978,062

VARIABLE HEIGHT SCAFFOLD ASSEMBLY a J ag VARIABLE HEIGHT 'SCAFFOLDASSEMBLY N.Y., a corporation of New York Filed June18, 1957, Ser. No.666,416

2 Claims (Cl. 181-1) Many construction and servicing operations, in par:ticular thoseinvolving maintenance of aircraft, require thatthescaifolding from which the work is performed be "set at variousheights. In the case of an airplane wing,

' United States Patent() Eugene J. Di Camillo, Lynbrook, and Donald I.Smith,

Oakda N Y asslgnors to Ausecoi Inc Brooklyn scaffold units mtegratedbeneath an airplane wing to form as well as motion controlling systemenergized by the forces attendant lowering of the platform.

A representative embodiment of the invention from which the above andother features and objects of the invention will be readily apparent isdescribed below having reference to the accompanying drawing in which:

Figure 1 is a view in sidefelevation showing a series of scaffoldassembly. I Figure 2 is an enlarged view in end elevation of thescaifoldunit of Figure 1, isolated from its companion scaffold unit, and,Figure 3 is an enlarged view inside elevation of a scaffold unitpartially elevated and showing a portion of a second unit joinedthereto.

Referring to the drawing, there are illustrated scaffold units 10, eachincluding a base 11 preferably mounted on caster wheels 11a forportability, and a vertically movfor examplegtheportion of the wingnearest the fuse- I lageis generally closest to the ground, the wingextending upwardly at an angle moving toward the tip, and ,vari ableheight scaffold units of a portable nature have been developed to servethis need. Each variable height unit,

however, is necessarily limited in working space and maintenance andconstruction crews have adopted the technique of bridging the spacebetween two or more scaffold units with temporaryplanking. Dangerouswork= ing conditions result. Moreover, presently used variable heightscaffolds are in the form of a platform carried at the free end of apivoted truss assembly adapted to he swung upwardly from a supportingbase in a large are. This results in displacement of the platformlongitudinally as it is swung upwardly, and it is often necessary toreposition theentire. assembly once the platform is elevated.

Both personnel and equipment are endangered by this able platform 12joined to the base ll through a lifting truss assembly indicatedgenerally by the numeral 13. The lifting truss 13 can take the form of apantograph type linkage including, working from the base upwardly, afirst pair of beams 14 and 15 (best seen in Figure 2) hinged throughpivotal connections 14a and 15a to upstanding U-shaped'lugs 16 and 17afiixed to the base 11. A second pair of beams 18 and 19 are'also hingedto the base 11 through pivotal connections 18:: and 19a, re= spectively,including upstanding U-shaped lugs 20 and 21, also fixed to the base.The upper ends of the'beams 14 'and 15 are hinged through pivotalconnections 14b and 15b, respectively, to the lower ends of a third pairng f beams 22 and 2 3, the upper ends of which are in turn hingedthrough pivotal connections 22a and 23a to the platform "12, thecoupling to the platform being com pleted through downwardly facingU-shaped. lugs 24 and 25, respectively. The upper ends of the beams18and 19 are similarly hinged through pivotal connections 18a and 19a tothe lower ends of beams 26 and 27, respectively, which are in turnhinged at their upper ends to the'plat form 12 through pivotalconnections 28 and 29, the latterincluding downwardly facing U-shapedlugs '30 'and 31;

Another object of the invention is to provide an adjustable scaffoldwhich is stable in all positions of adjustment. Another object of theinvention is to provide a scaffold assembly which entirely dispenseswith the need for makeshift bridging planking in elevated positions.

' In accordance with the present invention, there is provided a scaffoldassembly including a platform mounted for straight vertical movementrelative to a supporting base, which can be of the Wheeled variety forportability. Pivotally attached to the platform is a stairassembly,theopposite end of which rests on the ground at a" point spacedfrom the platform. The grounded end of the stair assembly includes-aground support enabling it to be readily carried along with the portablesupport base and also to shift inwardly along the ground as the platformrises from a fixed location, the stair treads being individually pivotedand coupled to control linkage so that they are at all times in ahorizontal plane. The design of the scaffold units issuch that two ormore can be readily integrated by joining the normally grounded end oforient the stair assemblies to the platform of "anotherscaffold unit. Inthis fashion the stair treads, now disposed'horizontally-in a commonplane, afford anelongated working-space between two scaffold units, theentire elevated working space being fully protected by fixed railings,upstanding margins and other safety features.

Joined in the pivotal connections 18a and 19a, respectively, are bracingbeams 32 and 33, the lower ends of which are hingedto the beams 14 and15, respectively; in'pivotal connections 34 and 35 near the lower endsof the beams 14 and 15. Similarly, a pair of bracing beams 36 and 37 arejoined at theirlower ends in the an amount corresponding approximatelyto the spacing of the pivotal connections 34 and 35 from the lower endsof the beams 14 and 15. For lateral stabilization, cross bridging isinserted between beams 18 and 19, in the form of a pair of traversemembers 40 and 41 bridged by a diagonal member 42. Similarly, the upperpair of beams 26 and 27 are reinforced by cross members 43 and 44 and adiagonal member 45. V v e In order to raise the platform 12 from thesupporting base 11, lift means in the form of a jack 46 is disposedbetween a cross member 46a and a corresponding cross member 11a on thebase 11; The member 46a is linkedto thebeams 14, 1 8 at one of its endsand to the beams 15, 19 at its other end, pivotal connectionsbeingeffected at each joint. The jack is adapted to be actuated by means of acontrol assembly 47 mountedjon the plat- Also, in accordance with'theinvention, the vertically movform 12 and coupled to the l throughhigh-Pressure able platform can be'power driven through the agencytubing 48 which can be either flexible throughout or f a pneumatic:drive including an energy recovering flexible at its curved portions toaccommodat 9 Patented Apr. 4, 1961 i tical motion. The control assembly47 can take the form of a pressure source, such as a storage tank or apump, actuated by a handle 47a, and suitable valve control means, notshown, for directing fluid to or from the jack.

In order to secure the movable platform 12 in any one of its range ofpositions, locking means in the form of a slotted and notched arm 64is'pivotally connected to the beam 22 of one end with a pin 65 fixed tothe platform 12 being received in its notched slot. As the platformrises, the locking means automatically secures it in successively higherpositions. form, it is necessary that the operator, in addition tomanipulation of the control assembly 47, hold the looking means in itsinoperative position freeing the pin 65 from the notches. A safety catchcan be engaged with the arm 64 to prevent accidental release. When thescaffold is in use, it is advisable to disable the caster wheels of thebase. To this end, anchoring pads are provided to engage the ground, thepads preferably being carried by extendable arm means for supplementarysupport against tipping.

The platform 12 is protected on two of its sides by handrails 66 and 67and on its third side by the removable chain 68. The fourth side is theapproach through which access to the platform is gained, this side beingthe terminal or upper end of a stairway assembly indicated generally bythe numeral 69. The, assembly 69 includes a pair of stretcher orcarriage beams 70 hinged at their upper ends to the platform 12 inpivotal connections 71 and joined at their lower ends by fixedcrosspiece 72 in which caster wheel means 73 are mounted. Each stretcher70 carries a hand or safety rail 74, and, at the upper end of the siderails 74, the rails 66 and 67 on the platform 12 are formed withextensions 66a and 67a bridging the generally triangular spacetherebetween the extensions being slightly laterally offset from thehand rails 74 for reasons presently to be described. The stretchers 70carry a series of treads 75 in the form of plate members hingedlyconnected to the risers by means of pivotal connections 76 adjacenttheir inner edges. 77, the respective free ends of which are pivotallyconnected to a common control bar 78 extending generally parallel to thestretchers 70 and terminating in a pivotal connection 79 (see Figure 2)to a depending anchoring To lower the platmon horizontal plane, forminga continuous surface from which repair and maintenance operations can beconducted. The side rails, without repositioning or alteration, fullyprotect the horizontal runway. In addition the pivotal connectionbetween each stair tread and the stretcher 70 is such that an upstandingsafety lip or edge results.

In certain cases, corresponding platforms 12 of two integrated units maybe necessarily disposed at slightly different levels, as might be thecase, for example, when servicing an airplane wing. Normally, asignificant variation in-heights would break up the coplanar arrangementof the stair treads which form the surface of the bridging memberbetween the two units. In accordance with the present invention, thepivotal connection 79 between the stair tread control bar 78 and thefixed depending lug 80 can be disabled to afford lost motion in eitherdirection over a distance determined by the length of a slot 84 in themember 80. By shifting the axis of the pivotal connection 79 along thelength of'the slot 84, the stair treads 75 can be maintained coplanarnot only in a horizontal plane, but in the slightly angled plane of thestretchers 70, thus forming an inclined but smooth runway betweenplatforms. In those cases in which the platform 12 is relatively closeto the ground, the horizontal positioning of the stair treads 75 can beshifted into the plane of the stretchers to form a Each tread 75 hassecured thereto a rocker arm lug 80 secured to the platform 12. Thestair tread connections are such that for every angular position of thestretchers 70, the stair treads 75 are held in a horizontal position. Inthis fashion, as the platform 12 is lifted, the stairway remains useableat all times, the grounded end of the stairway rolling inwardly on itswheel means 73 as the platform rises.

In the event two staging units 10 are used together, the stairwayassembly 69 of one unit is convertible in accordance with the presentinvention into a bridging platform by swinging it upwardly into thehorizontal plane of the platform 12 and securing the normally groundedend thereto. As illustrated in Figure 2, for example, the stair andplatform assembly 69, shown at the upper left-hand portion of the figureand constituting a stair assembly identical to that 69 of the stagingunit 10,

has been coupled to the platform 12 by means of a cou pling indicatedgenerally by the numeral 80. The coupling 80 includes an L-shapedchannel 81 adjacent the normally grounded end of the stair assembly andreceived in a channel 82 formed at the edge of the platform 12. It willbe recalled that this edge of the platform is normally bounded by theremovable chain 68. Preferably, a rubber bumper 83 is secured to theexposed edge of the platform 12 on three sides both to protect equipmentbeing serviced from damage and to tighten the coupling 80 between matedstaging units. With the stair assembly 69' disposed in a horizontalplane, each of the stair treads 75 will be disposed in a comsmooth rampleading from the ground to the platform 12. Thus, if desired, heavyequipment can be wheeled on a dolly to the platform 12 before it israised. Also, the inclined ramp can be used as the last stage of aseries of the ramp section, not part of the illustrated equipment,leading from the ground to the raised platform.

It will be understood that any number of basic units can be combined toform, for example, stagings extending the entire length of an airplanewing or extending all around a building under construction and fromwhich masons, for example, can work, raising the platforms as one astheir work progresses upwardly. While the invention has been illustratedand described above having reference to a particular embodiment thereof,it will be understood that it can take various other forms andarrangements within the scope of the present invention which should nottherefore be regarded as limited except as defined in the followingclaims.

We claim:

1. A scaffold assembly comprising a supporting base, a work platform,linkage means between the base and the platform for guiding the platformin vertical motion, jack means for raising and lowering the platform,access stairway means including a bank of stair treads, means to pivotally secure said bank at its upper end to said platform;

means to support the lower end of said bank on the ground to move towardand away from the base as the platform is respectively raised andlowered, said treads each being pivotally mounted in the bank forswinging movement on a horizontal axis, and control linkage means joinedto each of said treads and responsive to pivotal movement of the bankrelative to the platform to maintain the threads in a horizontal plane,said stairway including first securing means adjacent its normallygrounded end remote from the platform, said platform including on anedge other than that of the pivotal connection of the stairway, secondsecuring means complementary to that of the stairway, whereby twolaterally spaced apart scaffold assemblies can be integrated by unitingthe first and second securing means disposed respectively on theplatform of one assembly and the stairway of the other assembly to forma bridging platform between the two vertically movable platforms, saidstairway tread control means driving the treadsof the bridging stairwayinto coplanar relationship.

-2. A scaffold assemblycomprising a supporting base,

a work platform, linkage means between the base and the platform forguiding the platform in vertical motion, jack means for raising andlowering the platform, access stairway means including a bank of stairtreads, means to pivotally secure said bank at its upper end to saidplatform, means to support the lower end of said bank on the ground tomove toward and away from the base as the platform is respectivelyraised and lowered, said treads each being pivot-ally mounted in thebank for swinging movement on a horizontal axis, and control linkagemeans joined to each of said treads and responsive to pivotal movementof the bank relative to the platform to maintain the treads in ahorizontal plane, including lost motion means selectively adapted todisable the control means for the treads to maintain the treads in ahorizontal plane, whereby the stair treads can be swung into coplanarrelationship at angles slightly above or slightly below the horizontal.

References Cited in the file of this patent UNITED STATES PATENTSPeterson June 17, 1884 Fellows June 13, 1922 Havens June 3, 1930 BirdJuly 4, 1933 Bailey Ian. 23, 1934 Swaisgood Nov. 7, 1944 Conrad Apr. 5,1949 Ross May 31, 1949 Sensenbaugh Jan. 13, 1953 Middendorf June 12,1956 Cash July 2, 1957 FOREIGN PATENTS Great Britain Sept. 26, 1928

